Use the following links to compare to what you see on a roof:
Functional damage:
1. Shortens expected service life
2. Reduces ability of roof to shed water
"Functional Damage" is an important term to insurance companies and shingle manufacturers. Take this definition into account when evaluating roofs.
- Asphalt Shingle Inspection Concerns;
- 2021 IRC R905.2 Asphalt Shingles;
- Mastering Roof Inspections ; (Asphalt Shingles (#55-#109)
- Asphalt Shingle Inspection Field Guide, $18.99, by Kenton Shepard
- Inspecting Shingle Bonding;
- Craze-cracking;
- Identifying Wind Damage;
- Batch Problems;
- Blisters VS Hail Damage;
- Biological Growth;
- Uniform Granule Loss;
- Racking of Shingles(GAF Technical Advisory Bulletin)
- Buckling of Shingles
- White/Brown Stains below Roof Vents;
- The History of Asphalt Shingles(CASMA)
- Asphalt Shingle Sealant Strips(Donan Engineering)
- Impact Resistance of Asphalt Shingles (Insurance Institute for Business and Home Safety)
- 66 GAF Technical Bulletins
- Telescoping Ladder Maintenance
- FM Global: Roof Inspection Resources
- Asphalt Roofing Manufacturer's Association
- InterNACHI Asphalt Shingle Inspection online video course(3.25 hrs, InterNACHI members only)